What is a High Pass Filter ?

A High Pass Filter is a filter which permits high frequency signals to pass through and blocks only low frequency signals. The high pass filter has a relatively simple construction. The filter can be constructed by either providing a low impedance path to high frequency signals from the input to the output or by providing a low impedance path to low frequency

If a capacitor is connected in series between the input and the output, it will provide low impedance to high frequency signals and high impedance to low frequency signals. High frequency signals alone will be able to pass the capacitor.

Alternatively, if an inductor is connected in parallel to the input, it will offer low impedance to low frequency signals which will get shorted across the input. High frequency signals will alone reach the output.